To the Editor: Dr Jencks and colleagues1 reported that states' performance on 22 indicators
of medical quality improved by an overall 3% between 1998-1999 and 2000-2001
although there was significant variation between states. The data were quite
complex; with 52 state rates for 22 quality indicators, there was a total
of 1144 individual outcomes. The authors assisted interpretation of this large
data set by providing a state ranking for each indicator and calculating an
overall state ranking using the average of individual indicators' relative
rankings. Studies have found, however, that most people can generally assimilate
only 5 to 7 variables in such a quality assessment.2